How Gravity-Flow Wineries are Taking Grapes to New Heights

Somewhere between industrialized winemaking and the full-on natural/no-intervention movement, there are a growing number of producers using the environment—and more importantly, gravity—to refine their winemaking technique. Many believe that removing pumps or motors from the winemaking process preserves better fragrance and flavor. Some wineries have even gone so far as to build their facilities underground or on sloped land to bypass machinery and let gravity better work its magic.

Are these environmental efforts the future or just a fad? Owners and winemakers from five wineries around the U.S. and Canada speak about how their environmentally-friendly production techniques influence the quality of the resulting wines.

“By avoiding shaking, bruising, emulsion [or] oxidation, we are able to preserve the purity of fruit and negate astringency and compromising flavors. Aromatics are kept within the wine.” –Jean-Laurent Groux, winemaker, Stratus Vineyards

The tasting room of Stratus Vineyards

Stratus Vineyards

Jean-Laurent Groux, or “J-L,” is the winemaker at Stratus Vineyards in Niagara, one of the few completely pump-free wineries in the world.

“By avoiding shaking, bruising, emulsion [or] oxidation, we are able to preserve the purity of fruit and negate astringency and compromising flavors,” says Groux. “Aromatics are kept within the wine.”

To do this, Stratus utilizes a four-story production facility, certified by the Leadership in Energy and Environmental Design (LEED) organization, which allows for the movement of wine from the upper levels of the facility to those lower, while keeping oxygen contact and aeration to a minimum. In addition to their production design, Stratus also makes a point of using 100% hand-harvested grapes.

“The pursuit of optimal quality and form following function drove the entire process at Stratus,” says Groux. “As we were a completely new build, we were able to incorporate ‘ideal’ scenarios for the noninterventionist movement of fruit, juice and wine. [The harnessing of] gravity, being an age-old concept, [is] still highly relevant to premium winemaking.”

Keeping a close eye on the process at Palmaz Vineyards / Photo by Nicola Majocchi

Palmaz Vineyards

Tannin polymerization occurs as a wine ages. It’s the process by which tannin molecules bind together and fall out of suspension as sediment, which smooths out the texture and mouthfeel of the wine.

“Ever since it has been known that the tannin molecules in wine are polymerizing structures, there has been a great benefit to being as gentle as possible during the winemaking process,” says Palmaz.

The facility, which spans 18-stories underground, was engineered so that the gravity alone is enough to transport the fermented wine, as well as filter it and allow for blending with minimal agitation. The distance between the levels even creates enough pressure for bottling without pumps.

Palmaz Vineyards exterior and their subterranean production facilities / Photo by Lance Hitchings

“Tannin polymerization is limited or even degraded by the mechanical shear caused by pumps,” Palmaz says. He maintains that when wine is made with machines, it doesn’t get the chance to rest until it hits the bottle, resulting in added aging responsibility for the wine’s buyer.

Not only does the facility reduce electricity consumption, “[it’s] one of the only certified net-zero water consumption wineries in California,” says Palmaz. “This means that every drop of water used in the process of making wine is captured, treated back to nearly potable standards, stored in a tunnel three city blocks long, and then used for irrigation the following year.”

“This amounts to over 1.5 million gallons of water saved every year and reused for irrigation,” he says.

These methods also allow the winery to scale back on equipment used, allowing for further conservation by decreasing the amount of water and resources needed to clean equipment like pumps.

“Our facility’s non-compromising approach to gravity flow ensures that any polymerization achieved during the process of aging wine [in tank or barrel] is maintained to the bottle,” says Palmaz. “Since, arguably, the wine is progressively more molecularly delicate as tannin polymers form, we have dedicated the design of Palmaz Vineyards to be truly gravity from start to finish…hence why we like to call our process ‘gravity finished.’ ”

“[Avoiding pumps] protects the delicate aromatic compounds in Pinot Noir. The wines are made in a reductive environment for the most part, ultimately leading to freshness and purity in the bottle.” –Melissa Burr, vice president of winemaking, Stoller Family Estate

Stoller Family Group

At Oregon’s Stoller Family Estate, in the Willamette Valley’s Dundee Hills, it was fairly easy to embrace the gravity-flow method, says Melissa Burr, the winery’s vice president of winemaking.

“We utilized the natural topography of the hillside on the Stoller estate to build the winery, and incorporated the slope to create a multilevel gravity-flow facility,” says Burr. “The advantage of using gravity to move wine from fermentation to settling, and then to barrel for gentle processing and treatment of wine, was part of the design.”

According to Burr, these techniques reduce oxygen contact in the final wines.

“This protects the delicate aromatic compounds in Pinot Noir,” says Burr. “The wines are made in a reductive environment for the most part, ultimately leading to freshness and purity in the bottle.”

Making full use of the hillside’s benefits, the winery utilizes natural insulation in the cellars. The first LEED Gold winery in the world, Stoller’s cellar is completely underground, keeping it cooler in the summer and warmer in the winter. Catacombs also wind throughout the facility, facilitating air movement and helping create consistent temperatures without artificial heating or cooling.

Stoutridge Winery

Stephen Osborn, the owner, winemaker and distiller at Stoutridge Vineyard in New York’s Hudson Valley, decided to ditch machine methods for two main reasons.

“First, it’s more environmentally friendly,” says Osborn. “No electric motors and less things to clean with hot water and cleaning agents. Second, it makes fresher-tasting wine.”

Also contributing to sustainability efforts, Stoutridge powers both the production facilities as well as areas open to the public through photovoltaic solar panels mounted on the south-facing roof. The winery also utilizes a system to capture heat created during the winemaking process to help warm outdoor areas as well as the floors of the tasting room.

“It’s a lot like the difference between a puréed tomato and a whole tomato—the purée always tastes less fresh and visceral, even though the chemistries of the two are identical.” –Stephen Osborn, owner/winemaker/distiller, Stoutridge Vineyard

But what is it about the gravity technique that allows for a fresher style of wine?

“Lack of pumping and filtration helps to retain the dissolved [carbon dioxide] from fermentation in the finished wine, which alters the flavor profile globally,” says Osborn. “So it’s a texture value, dissolved gasses, affecting the entire flavor profile of the wine. It becomes fresher tasting and more vibrant.

It’s a lot like the difference between a puréed tomato and a whole tomato—the purée always tastes less fresh and visceral, even though the chemistries of the two are identical.”

Lemelson Vineyards

According to Eric Lemelson, owner/founder of Lemelson Vineyards in the Willamette Valley, they settled on gravity flow for one reason.

“I wanted to make the most nuanced, complex, highest-quality wine from the wine grapes we grow in all of our seven sites,” says Lemelson. “Gravity flow is one of many choices we make that affect the complexity of the final product.

Matt Wengel, head winemaker at Lemelson, describes the winemaking process. The fruit is first hand-picked, then placed on the elevated sorting platform above the tank.

“Individual berries or clusters literally fall into the [fermenting] tank one by one, as opposed to using a must pump or dumping processed half-ton fruit bins into the tank via forklift,” he says. “What this means is that we can get a higher proportion of whole berries in our tanks over the other two methods, and we avoid mechanical shearing of the berries which can easily be caused by must pumps.”

Lemelson sees these techniques as one part of a greater whole when it comes to making quality wine. “While I know that you can make great wines using pumps, and that employing low-pressure, gravity-based winemaking does not guarantee anything at the end of the day, I still believe that it’s the better qualitative choice,” he says.

Lemelson, who has a degree in environmental law, also volunteers for a number of ecological causes, including the Oregon Global Warming Commission, as well as the conservation group 1000 Friends of Oregon. He also sits on the board of directors of The Lemelson Foundation, which aims to support inventors and innovators, with a focus on strengthening the planet’s ecosystem. However, he does admit that his eco-friendly winemaking techniques aren’t a complete panacea for the planet.

“Everything we do, seemingly, has implications in terms of energy and materials used that affect our emissions and…the global ecosystem,” says Lemelson.

But the producer does see stark differences in the final wine.

“What this translates to is softer, rounder tannins and mouthfeel in the resulting wines, as well as an enhanced red-fruit character similar to that of carbonic maceration,” says Wengel. “Mechanical damage to the berry skins, and particularly the seeds, will cause unwanted, harsher tannin release before the tank even starts fermenting.”